FOREARM, WRIST, AND HAND. 



ment; hook of unciform. Insertion ; inner side of first pha- 

 lanx of little finger. [347] 



Palmar Interossei. These are three muscles which occupy 

 the three inner interosseous spaces; each arises by a single 

 head and is inserted into the dorsal expansion of the extensor 

 tendon, the capsule of the metacarpo-phalangeal joint, and the 

 side of the first phalanx of its finger. Origin ; (first) ulnar side 

 of shaft of second metacarpal ; (second and third) radial sides 

 of shafts of fourth and fifth metacarpals, respectively. Inser- 

 tion; (first) ulnar side of second finger; (second and third) 

 radial sides of fourth and fifth fingers respectively. [347] 



Dorsal Interossei. These are four muscles which occupy 

 the interosseous spaces and are inserted like the Palmar inter- 

 ossei. Origin ; sides of metacarpal bones bounding each inter- 

 osseous space, by two heads. Insertion ; (first and second) ra- 

 dial sides of index and third fingers and (third and fourth) 

 ulnar sides of third and fourth fingers respectively. [347] 



Back of Forearm. Superficial Layer. 



Brachio-radialis. Origin; upper two-thirds of external 

 supracondyloid ridge of humerus ; external intermuscular sep- 

 tum. Insertion; ridge on front of base of styloid process of 

 radius. [349] 



Extensor Carpi Radialis Longior. Origin; lower third of 

 external supracondyloid ridge of humerus; external inter- 

 muscular septum; external condyle, by the common tendon. 

 Insertion; back of base of second metacarpal. [349] 



Extensor Carpi Radialis Brevior. Origin; external con- 

 dyle of humerus, by the common tendon; external ligament 

 of elbow ; fascia over it ; intermuscular septa. Insertion ; back 

 of base of third metacarpal. [349] 



Extensor Communis Digitorum. Origin; external condyle, 

 by the common tendon; intermuscular septa. Course; it ends 

 in four tendons; on the back of the hand the inner three are 



[173] 



